When Jesus says, "The Father is greater than I," are we supposed to think that he is inferior to the Father? Does Jesus' prayer, "Not my will but yours be done," imply that Jesus is subordinate? Today, and throughout history, some people have concluded from such statements that Jesus is not fully God. In the fourth century, the Council of Nicaea condemned the teachings of Arius, a priest who had tried to make sense out of these perplexing questions by claiming that Jesus was a created being inferior to God. Heresies and How to Avoid Them: Why It Matters What Christians Believe (Hendrickson, 2007), a collection of essays edited by Ben Quash (professor of Christianity and the Arts at Kings College) and Michael Ward (chaplain at Peterhouse College in Cambridge), attempts to prevent modern Christians from stumbling upon ancient heresies by showing how the church dealt with these problems in the past.

The book is based on a series of sermons on the contemporary relevance of ancient Christian debates. Each chapter covers a different heresy on either the person of Christ, the nature of the church, or Christian living. Topics range from Docetism (the belief that Jesus only appears human) to Donatism (the belief that Christian ministers need to be flawless in order to administer the sacraments).

The contributors, who include both pastors and scholars, keep the tone practical by focusing on the lasting implications of each heresy covered. So, for example, we learn more about the dangers that the heresy of Arianism presents to modern Christians than we do about Arius himself and his condemnation. Each chapter ends with advice on how to avoid the contemporary forms of heresy. Suggestions range from participating attentively in worship to reconsidering the way one thinks about salvation.

According to the contributors, heresy is attractive because it appears to solve a specific problem, but it does so at the expense of the coherence of the Christian faith. Orthodoxy, on the other hand, protects the faith in its entirety. Each new heresy about the person of Christ, the church, or Christian living has caused the church to further refine its understanding of Christ's saving work.

A guiding principle of this book is that heretics are not villains but genuine truth-seekers. Gone is the usual list of theological errors and reasons to reject them. Instead, each essay begins with a sympathetic presentation of the heretic's position. According to Ben Quash, who authored the prologue, we "have reason to be grateful to heresies because they have forced us to think our belief out more deeply and thoroughly." By understanding the logic and motivation behind heresies, we can more fully appreciate the orthodox answers.

Another guiding principle is that differences in scriptural interpretation have always been at the heart of the church's doctrinal disputes. Quash notes that heretics-to-be were just as concerned about staying true to Scripture as orthodox thinkers. We need to be familiar with the biblical passages that sparked such debates in order to grasp the interplay between heresy and orthodoxy. Accordingly, every chapter begins by quoting the scriptural passages most relevant to each debate. Unfortunately, the chapters are too short to allow the authors to delve deeply into the biblical arguments.

The book concludes that the task of distinguishing heresy from orthodoxy is not simply a tool for organizing Christians according to a common belief system, but an exercise that leads to true worship of the Trinity. Thus the last chapter by Janet Soskice focuses on the positive elements of Trinitarian orthodoxy. For Soskice, the doctrine of the Trinity is more than just a dogmatic definition. It is primarily a practical doctrine because it reminds Christians that the presence of God the Father is available to human beings through the Son and the Holy Spirit.

Heresies and How to Avoid Them is directed towards a general rather than an academic audience. There are no footnotes, for example, and citations are kept to a minimum. In addition to the essays on each heresy, it also includes a helpful glossary of terms, suggestions for further reading, an index of biblical references, and a thorough general index. In this way, the book serves as a reference tool for anyone who desires an introduction to the development of Christian doctrine.

Jason Scully is a doctoral student in patristic theology at Marquette University.